Silk is one of the best material for underwear,the silk long johns is Soft ,comfortable and lightweight,Silk fabric is also very breathable and antistatic,it's good for skin health,as thermal underwear or base layer for women ,Great to be Wear Alone at Home or Add an Extra Layer of Warmth Under Your Clothes. . Size details as below,Please according to the size information and choose the suitable size Size details of the clothing as below:(inches) Small size: Chest:35"-37", Top Length: 23". Pants outseam: 38", Elastic Waist: 25"-32". Medium size: Chest 37"-39", Top Length: 24". Pants outseam: 39", Elastic Waist: 28"-32". Large size: Chest 39"-43" , Top Length: 24". Pants outseam: 40",Elastic Waist: 29"-35". X-Large size: Chest 42"-45" , Top Length:25.2". Pants outseam: 41",Elastic Waist: 30"-39".